1. Field of the Invention
The present invention is related to mine roof bolting machines and, more particularly, is directed towards a combination riding cab and protective canopy for the operator of a mine roof bolting machine.
2. Description of the Prior Art
Mine roof bolting machines are in common use, and generally comprise a wheeled vehicle approximately eight feet wide, twelve to twenty feet long, and approximately thirty inches high, at most. Positioned at the front of the roof bolter is a vertically movable boom which has a drill head mounted thereon. The drill head is adapted to drill a one and one-half inch diameter hole to a depth of four feet, six feet, eight feet, or the like. After the hole is drilled, a roof bolt is inserted and secured by means of an adhesive and hardener, the completed assembly acting to support the lower face of the roof.
Many roof bolting machines are provided with an operator's station which includes hydraulic controls arranged in a valve bank. The controls permit the operator to both drill holes and travel with the machine inside the mine from place to place, i.e., tramming.
It is known to provide a fixed overhead canopy at the rear of a roof bolter to provide the operator with some protection while the machine is trammed. When the desired drilling location is reached, the operator must get out of the rear canopy and move to the front of the machine where the holes are drilled and bolts are installed. This arrangement, in turn, required two canopies: one installed at the rear of the bolter for protecting the operator while tramming, and one installed at the front of the bolter to protect the operator while drilling and installing the bolt. A clear drawback of this arrangement requires the operator to leave the rear cab to reach the front control panel during which time he is exposed and subjected to a possible roof fall and concomitant serious injury.
It would be extremely advantageous if a unitary cab and canopy assembly could be provided which did not dangerously expose the operator during the tramming or drilling operation of a roof bolting machine.
Another disadvantage of prior art roof bolting machines is that the operator's cab from which the controls must be handled is generally rigidly attached to the roof bolter itself. Due to the general unevenness of the floor of the mine, the operator experiences tremendous rocking motions fore and aft during tramming. Since the operator's cab is fixed to the bolter, this motion is transmitted to the operator and encourages abnormal movements of the arms which can lead to erratic operation of the controls. It would be highly advantageous if control of the roof bolter during tramming could be increased.
I am aware of the following United States patents which teach the desirability of utilizing a cab and canopy for mine vehicles: U.S. Pat. Nos. 2,325,731; 2,496,694; 3,315,758; 3,398,984; and 3,937,517.